View Full Version : IBM PS/2 Model L40SX - MB damage, help

Lord Nightmare
March 30th, 2009, 07:15 PM
I disassembled an L40SX I acquired a while back to repair some main-battery-leakage related corrosion on the back connector panel. When I did, I discovered that one of the components on the MB had, at some point, lost its magic smoke. The system still seems to work, but I'd like to know what that component is for future repair. (one of the main battery 'contacts' is also snapped in half and needs replacement)

It is located at Q9 (underneath the floppy drive, next to two capacitors, one of which had burst and leaked brownish goo, probably related to the failure of the component). The component is about 3mmx6mm, and I can't really read the label to know what it is to replace it with, as the surface is melted.

It may be related to charging the main battery (or the standby battery), or perhaps for switching power to the serial and parallel ports on the back, which I did not test.


Terry Yager
March 31st, 2009, 12:22 AM
It's a transistor, that's all I can tell ya without tearing mine down, which I'm disinclined to do at the moment.


Terry Yager
March 31st, 2009, 11:50 AM
OK, here we go. Q9 is marked:

M R13

Don't ask me what that means, but it's sum'n.

Q9 is quite some distance from the main bat, so if it's bad from leakage, expect some other problems as well, 'specially with all those lil' do-dads in between.